JP6640451B2 - Residual stress evaluation method - Google Patents

Description

  The present disclosure relates to a method for evaluating residual stress improved by performing water jet peening, a program for executing the method, and an apparatus for executing the method.

  Stress corrosion cracking (SCC) is known as one of the degradation phenomena of a structure (metal or the like) in high-temperature water. When the cause of the SCC is a residual tensile stress generated in a weld or the like, water jet peening (hereinafter, referred to as WJP) may be applied to the structure as a measure to prevent the deterioration. This WJP is a technology capable of improving residual stress in the vicinity of the surface of a structure (object) and is a technology that can be constructed in water. More specifically, in WJP, high-pressure water is jetted from a nozzle to the surface of an object, and plastic deformation is applied to the surface of the object by utilizing the impact pressure at the time of collapse of bubbles (cavitation bubbles) generated by this injection. Wake up. Then, through such plastic deformation, the residual stress near the surface of the object is reduced, or the tensile residual stress near the surface is improved to the compressive residual stress, thereby suppressing SCC.

  On the other hand, several methods for evaluating the residual stress of a structure after WJP is applied have been proposed, and Patent Literature 1 below discloses a method for estimating the residual stress of a construction site. Specifically, in Patent Document 1, the collapse pressure of cavitation bubbles can be obtained based on the correlation between the residual stress after WJP construction and the collapse pressure of cavitation bubbles and the cavitation energy acting on the surface to be subjected to WJP construction. Based on the knowledge, the cavitation energy is calculated using the internal pressure and the number density of the cavitation bubbles obtained by analyzing the jet flow ejected from the nozzle, and the collapse pressure of the cavitation bubbles is calculated based on the cavitation energy. The residual stress after the WJP on the construction target surface is calculated using the collapse pressure.

Japanese Patent No. 50111416

  As described above, in Patent Document 1, the collapse pressure of the cavitation bubble is obtained based on the analysis result of the cavitation energy (the internal pressure of the cavitation bubble and the bubble number density). In contrast, in the present disclosure, attention is paid to the occurrence and disappearance of cavitation bubbles in WJP, a correlation value that correlates to the actual impact pressure generated by cavitation bubbles is obtained by analysis, and the analyzed correlation value and the experimental value are calculated. It has been newly found that it is possible to predict the distribution of the actual impact pressure caused by the cavitation bubbles (impact pressure at each position on the construction target surface) by associating them. Then, the residual stress after WJP construction is evaluated from the predicted value of the impact pressure.

  In view of the above circumstances, at least one embodiment of the present invention aims to provide a method for evaluating residual stress based on an analysis of the generation and disappearance of cavitation bubbles in water jet peening (WJP).

(1) The residual stress evaluation method according to at least one embodiment of the present invention includes:
A condition setting step of setting water jet peening construction conditions for the construction object,
Analyzing the jet flow when the fluid is jetted from the nozzle model to the construction target model according to the construction conditions, at each position on the surface of the construction target model, the volume fraction of bubbles contained in the unit volume of the fluid An analysis step to determine the void fraction, and the collapse rate, which is the volume fraction of the bubbles that collapse in a unit time in the unit volume of the fluid,
Impact pressure correlation value calculation step of obtaining an impact pressure correlation value that is a product of the void rate and the collapse rate at each position,
An experimental value acquisition step of acquiring an impact pressure experimental value that is an experimental value of an impact pressure acting on the surface of the construction target by the water jet peening according to the construction condition,
The impact pressure correlation value at each position of the surface of the construction target model, and the impact pressure experimental value acting on the surface of the construction target by the water jet peening according to the construction condition, the impact pressure experimental value according to the construction condition Prediction step of obtaining an impact pressure predicted value that is a predicted value of the impact pressure acting on each position of the construction target surface by water jet peening,
A residual stress evaluation step of calculating a residual stress in the construction target after the water jet peening under the construction conditions, using the impact pressure predicted value acquired in the prediction step as an input condition.

  According to the configuration of the above (1), by analyzing the occurrence and disappearance of cavitation bubbles in water jet peening (WJP), the distribution of the actual impact pressure due to WJP generated near the construction target surface (each of the construction target surface) (Impact pressure at the position), and the residual stress after WJP construction can be evaluated based on the predicted impact pressure.

(2) In some embodiments, in the configuration of the above (1),
The shock pressure predicted value is obtained by determining a coefficient k that associates the shock pressure correlation value at each position on the surface of the construction target model with the shock pressure experimental value.
According to the configuration of the above (2), by determining the coefficient k, it is possible to associate the shock pressure correlation value at each position on the surface of the construction target model with the shock pressure experiment value. It is possible to analyze and evaluate the actual residual stress after the water jet peening (WJP) in the vicinity of the target surface.

(3) In some embodiments, in the above configurations (1) and (2),
A target value setting step of setting a target value of the residual stress,
An execution condition changing step of changing the execution condition when the residual stress does not satisfy the target value,
The analysis step, the impact pressure correlation value calculation step, and the re-evaluation step of performing the residual stress evaluation step by the changed execution condition changed by the execution condition changing step,
When the residual stress calculated by the re-evaluation step satisfies the target value, a construction condition determination step of determining the construction condition used in the re-evaluation step as the construction condition for the construction target, Further prepare.
According to the configuration of the above (3), on the basis of a comparison between the target value of the residual stress and the analysis value of the residual stress after the water jet peening (WJP) is performed under an arbitrary processing condition, the processing condition satisfying the target value Is determined. For this reason, even when WJP is performed under construction conditions that have no track record in accordance with plant specifications, the residual stress after WJP construction can be evaluated by analysis, and appropriate construction conditions according to plant specifications can be determined. Can be determined promptly. Furthermore, reliable WJP construction can be performed by actually constructing WJP according to the construction conditions determined in this way. Further, the present invention can be used for designing a WJP construction apparatus capable of performing construction under desired construction conditions.

(4) In some embodiments, in the configuration of the above (3),
If the residual stress calculated by the reevaluation step does not satisfy the target value, further change the execution condition by the execution condition change step, the changed execution condition further changed by the execution condition change step Performs the reevaluation step.
According to the configuration of the above (4), when the evaluation result of the residual stress after the water jet peening (WJP) under the arbitrary construction conditions does not satisfy the target value, the similar evaluation under the other arbitrary construction conditions Is performed. As a result, it is possible to determine the construction condition that satisfies the target value.

(5) In some embodiments, in the above configurations (1) to (4),
The execution conditions are: water jet injection time by the water jet peening, the water jet injection speed, the water jet flow rate, the water jet peening execution range, the water jet injection distance, the bubble radius, and the nozzle. And at least one of an angle and a tilt angle of the surface to be applied.
According to the above configuration (5), since various conditions that may affect the residual stress after WJP are included in the execution conditions, it is necessary to accurately evaluate the residual stress after WJP under any arbitrary conditions. Can be.

(6) The water jet peening evaluation program according to at least one embodiment of the present invention includes:
On the computer,
A condition setting step of setting water jet peening construction conditions for the construction object,
Analyzing the jet flow when the fluid is jetted from the nozzle model to the construction target model according to the construction conditions, at each position on the surface of the construction target model, the volume fraction of bubbles contained in the unit volume of the fluid An analysis step to determine the void fraction, and the collapse rate, which is the volume fraction of the bubbles that collapse in a unit time in the unit volume of the fluid,
Impact pressure correlation value calculation step of obtaining an impact pressure correlation value that is a product of the void rate and the collapse rate at each position,
An experimental value acquisition step of acquiring an impact pressure experimental value that is an experimental value of an impact pressure acting on the surface of the construction target by the water jet peening according to the construction condition,
The impact pressure correlation value at each position of the surface of the construction target model, and the impact pressure experimental value acting on the surface of the construction target by the water jet peening according to the construction condition, the impact pressure experimental value according to the construction condition Prediction step of obtaining an impact pressure predicted value that is a predicted value of the impact pressure acting on each position of the construction target surface by water jet peening,
A residual stress evaluation step of calculating a residual stress in the object after the water jet peening according to the application condition, using the impact pressure predicted value acquired in the prediction step as an input condition.

  According to the configuration of the above (6), by analyzing the generation and disappearance of cavitation bubbles in water jet peening (WJP), the distribution of the actual impact pressure due to WJP generated near the construction target surface (each of the construction target surface) (Impact pressure at the position), and the residual stress after WJP construction can be evaluated based on the predicted impact pressure.

(7) In some embodiments, in the configuration of the above (6),
The shock pressure predicted value is obtained by determining a coefficient k that associates the shock pressure correlation value at each position on the surface of the construction target model with the shock pressure experimental value.
According to the configuration of (7), by determining the coefficient k, it is possible to associate the shock pressure correlation value at each position on the surface of the construction target model with the shock pressure experiment value. It is possible to analyze and evaluate the actual residual stress after the water jet peening (WJP) in the vicinity of the target surface.

(8) In some embodiments, in the configuration of the above (6) to (7),
A target value setting step of setting a target value of the residual stress,
An execution condition changing step of changing the execution condition when the residual stress does not satisfy the target value,
The analysis step, the impact pressure correlation value calculation step, and the re-evaluation step of performing the residual stress evaluation step by the changed execution condition changed by the execution condition changing step,
When the residual stress calculated by the re-evaluation step satisfies the target value, a construction condition determination step of determining the construction condition used in the re-evaluation step as the construction condition for the construction target, Let it run more.
According to the configuration of the above (8), on the basis of a comparison between the target value of the residual stress and the analysis value of the residual stress after the water jet peening (WJP) under the arbitrary execution conditions, the execution condition satisfying the target value is obtained. Is determined. For this reason, even when WJP is performed under construction conditions that have no track record in accordance with plant specifications, the residual stress after WJP construction can be evaluated by analysis, and appropriate construction conditions according to plant specifications can be determined. Can be determined promptly. Furthermore, reliable WJP construction can be performed by actually constructing WJP according to the construction conditions determined in this way. Further, the present invention can be used for designing a WJP construction apparatus capable of performing construction under desired construction conditions.

(9) In some embodiments, in the configuration of the above (8),
If the residual stress calculated by the reevaluation step does not satisfy the target value, further change the execution condition by the execution condition change step, the changed execution condition further changed by the execution condition change step Performs the reevaluation step.
According to the configuration of the above (9), when the evaluation result of the residual stress after the water jet peening (WJP) under the arbitrary construction conditions does not satisfy the target value, the similar evaluation under the other arbitrary construction conditions Is performed. As a result, it is possible to determine the construction condition that satisfies the target value.

(10) In some embodiments, in the above configurations (6) to (9),
The execution conditions are: water jet injection time by the water jet peening, the water jet injection speed, the water jet flow rate, the water jet peening execution range, the water jet injection distance, the bubble radius, and the nozzle. And at least one of an angle and a tilt angle of the surface to be applied.
According to the configuration of the above (10), since various conditions that may affect the residual stress after WJP are included in the execution conditions, it is necessary to accurately evaluate the residual stress after WJP under any execution conditions. Can be.

(11) The water jet peening evaluation apparatus according to at least one embodiment of the present invention includes:
A condition receiving unit for receiving water jet peening construction conditions for the construction object,
Analyzing the jet flow when the fluid is jetted from the nozzle model to the construction target model according to the construction conditions, at each position on the surface of the construction target model, the volume fraction of bubbles contained in the unit volume of the fluid An analysis unit for determining a void fraction, which is a volume fraction of the bubble that collapses per unit time in a unit volume of the fluid, and
An impact pressure correlation value calculation unit that determines an impact pressure correlation value that is a product of the void rate and the collapse rate at each of the positions,
An experimental value acquisition unit that acquires an impact pressure experimental value that is an experimental value of an impact pressure acting on the surface of the construction target by the water jet peening according to the construction condition.
The impact pressure correlation value at each position of the surface of the construction target model, and the impact pressure experimental value acting on the surface of the construction target by the water jet peening according to the construction condition, the impact pressure experimental value according to the construction condition A prediction unit that acquires an impact pressure predicted value that is a predicted value of the impact pressure acting on each position of the surface of the construction target by water jet peening,
A residual stress evaluation unit that calculates a residual stress in the construction target after the water jet peening under the construction conditions, using the impact pressure predicted value acquired by the prediction unit as an input condition.

  According to the configuration of the above (11), by analyzing the occurrence and disappearance of cavitation bubbles in water jet peening (WJP), the distribution of the actual impact pressure due to WJP generated near the construction target surface (each of the construction target surface) (Impact pressure at the position), and the residual stress after WJP construction can be evaluated based on the predicted impact pressure.

(12) In some embodiments, in the configuration of the above (11),
The shock pressure predicted value is obtained by determining a coefficient k that associates the shock pressure correlation value at each position on the surface of the construction target model with the shock pressure experimental value.
According to the configuration of the above (12), by determining the coefficient k, it is possible to associate the shock pressure correlation value at each position on the surface of the construction target model with the shock pressure experimental value. It is possible to analyze and evaluate the actual residual stress after the water jet peening (WJP) in the vicinity of the target surface.

(13) In some embodiments, in the configuration of the above (11) to (12),
A target value setting unit for setting a target value of the residual stress,
An execution condition changing unit that changes the execution condition when the residual stress does not satisfy the target value,
When the residual stress satisfies the target value, further comprising a construction condition determining unit that determines the construction conditions used for calculating the residual stress as the construction conditions for the construction target,
The re-evaluation is performed by the analysis unit, the impact pressure correlation value calculation unit, and the residual stress evaluation unit according to the changed execution condition changed by the execution condition changing unit,
When the residual stress calculated by the reevaluation satisfies the target value, the construction condition determination unit determines the construction condition used in the reevaluation as the construction condition for the construction target.
According to the configuration of the above (13), on the basis of a comparison between the target value of the residual stress and the analysis value of the residual stress after the water jet peening (WJP) under the arbitrary processing conditions, the execution condition satisfying the target value is obtained. Is determined. For this reason, even when WJP is performed under construction conditions that have no track record in accordance with plant specifications, the residual stress after WJP construction can be evaluated by analysis, and appropriate construction conditions according to plant specifications can be determined. Can be determined promptly. Furthermore, reliable WJP construction can be performed by actually constructing WJP according to the construction conditions determined in this way. Further, the present invention can be used for designing a WJP construction apparatus capable of performing construction under desired construction conditions.

(14) In some embodiments, in the configuration of the above (13),
When the residual stress calculated by the re-evaluation does not satisfy the target value, further change the execution condition by the execution condition changing unit, and by the changed execution condition further changed by the execution condition changing unit. The reevaluation is performed.
According to the configuration of the above (14), when the evaluation result of the residual stress after the water jet peening (WJP) under the arbitrary construction conditions does not satisfy the target value, the similar evaluation under the other arbitrary construction conditions Is performed. As a result, it is possible to determine the construction condition that satisfies the target value.

(15) In some embodiments, in the above configurations (11) to (14),
The execution conditions are: water jet injection time by the water jet peening, the water jet injection speed, the water jet flow rate, the water jet peening execution range, the water jet injection distance, the bubble radius, and the nozzle. And at least one of an angle and a tilt angle of the surface to be applied.
According to the above configuration (15), since various conditions that may affect the residual stress after WJP are included in the execution conditions, it is necessary to accurately evaluate the residual stress after the WJP is executed under any execution conditions. Can be.

  According to at least one embodiment of the present invention, there is provided a method for evaluating residual stress based on analysis of a state of generation and disappearance of cavitation bubbles in water jet peening (WJP).

It is a figure showing roughly composition of a WJP evaluation device concerning one embodiment of the present invention. It is a flowchart which shows the implementation procedure of the evaluation method of WJP which concerns on one Embodiment of this invention. It is a figure for explaining the relation between the construction object surface and an injection nozzle concerning one embodiment of the present invention. It is a figure showing an injection nozzle concerning one embodiment of the present invention. FIG. 4 is a diagram for explaining a relationship between an impact pressure correlation value Pc, an impact pressure experimental value Pr, and an impact pressure predicted value Pp, corresponding to FIG. 3. FIG. 4 is a diagram for explaining an example of a pressure distribution of an impact pressure by WJP corresponding to FIG. 3. It is a figure for explaining other examples of pressure distribution of the impact pressure by WJP. It is a figure for explaining the example of specification of a plant. It is a figure for explaining other examples of specifications of a plant. It is a figure showing roughly composition of a WJP evaluation device concerning other one embodiment of the present invention. It is a flowchart which shows the implementation procedure of the WJP evaluation method which concerns on another embodiment of this invention.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. Absent.
For example, expressions representing relative or absolute arrangement such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly described. Not only does such an arrangement be shown, but also a state of being relatively displaced by an angle or distance that allows the same function to be obtained.
For example, expressions such as "identical", "equal", and "homogeneous", which indicate that things are in the same state, not only represent exactly the same state, but also have a tolerance or a difference that provides the same function. An existing state shall also be represented.
For example, the expression representing a shape such as a square shape or a cylindrical shape not only represents a shape such as a square shape or a cylindrical shape in a strictly geometrical sense, but also an uneven portion or a chamfer as long as the same effect can be obtained. A shape including a part and the like is also represented.
On the other hand, the expression “comprising”, “comprising”, “including”, “including”, or “having” one component is not an exclusive expression excluding the existence of another component.

FIG. 1 is a diagram showing functional blocks of a WJP evaluation apparatus 10 (hereinafter, WJP evaluation apparatus 10) for evaluating residual stress after construction of water jet peening (hereinafter, WJP) according to an embodiment of the present invention. It is.
The WJP evaluation device 10 evaluates in advance the actual residual stress (result of WJP execution) near the surface of the execution target 40 after WJP execution, before executing WJP on a structure such as metal (construction target 40). It is a device that can do it. The WJP evaluation device 10 may be a computer including a WJP evaluation program 34 as in the embodiment shown in FIG. Hereinafter, the WJP evaluation device 10 will be described as a computer including the WJP evaluation program 34.

  In the embodiment shown in FIG. 1, the computer including the above-described WJP evaluation program 34 includes a CPU 20 for performing various calculations, a memory 13 (main storage device) serving as a work area for the CPU 20, and an auxiliary storage such as a hard disk drive. And an apparatus 30. In addition, as illustrated in FIG. 1, the computer includes an input device 11 such as a keyboard and a mouse, a display device (output device) 12, an input / output interface 14 of the input device 11 and the display device 12, and a network. It may include a communication interface 15 for communicating with the outside, and a storage / reproducing device 16 for performing data storage processing and data reproduction processing on the disk-type storage medium M.

  In the example of FIG. 1, the WJP evaluation program 34 and the OS (Operating System) program 37 capable of preliminarily evaluating the WJP execution result of the execution target 40 are stored in the auxiliary storage device 30 in advance. . That is, the WJP evaluation device 10 of the present embodiment is obtained by installing the WJP evaluation program 34 on a computer. In the embodiment shown in FIG. 1, the WJP evaluation program 34 includes a flow analysis module 35 for analyzing a jet generated in WJP construction based on computational fluid dynamics (CFD), and a flow analysis module 35 for the flow analysis module 35. A residual stress analysis module 36 for obtaining a processing range by WJP based on the analysis result. These programs 34 and 37 may be loaded into the auxiliary storage device 30 from the disk-type storage medium M via the storage / reproducing device 16 or from an external device via the communication interface 15. 30. Note that the number of modules (35, 36) included in the WJP evaluation program 34 is arbitrary, and in some other embodiments, the WJP evaluation program 34 may be composed of one or more modules.

  Further, the auxiliary storage device 30 may further store various data used in the execution process of the WJP evaluation program 34. In the embodiment shown in FIG. 1, a flow analysis which is an analysis result of a jet generated when WJP is executed under the execution condition data 31 (described later) which defines the execution condition of WJP and various conditions constituting the execution condition data 31. Data 32 and WJP processing range data 33 are stored.

  The CPU 20 functionally includes a parameter receiving unit 21 that receives various parameters necessary for the analysis of the jet by the flow analysis module 35, a condition receiving unit 22 that receives the WJP construction conditions, and various conditions that constitute the construction condition data 31. A flow analysis unit 23 that analyzes a jet generated at the time of WJP construction, a target range receiving unit 24 that receives a target processing range related to a construction target, a void rate f and a collapse rate η of bubbles (cavitation bubbles) generated in the jet. The correlation value (impact pressure) of the void rate / collapse rate calculation unit 25 for determining the later described (impact pressure P) which is estimated to act on the surface of the construction object model 45 which is the construction object 40 modeled by bubbles generated by WJP A shock pressure correlation value calculation unit 26 for calculating a correlation value Pc (described later) and construction by WJP under the above construction conditions An experimental value acquisition unit 27 that acquires an impact pressure experimental value Pr that is an experimental value of the impact pressure P acting on the surface of the elephant 40, and an impact pressure correlation value Pc (impact pressure correlation value) at each position on the surface of the construction target model 45. (Distribution of Pc) and the impact pressure experimental value Pr acting on the surface of the construction subject 40 by WJP according to the construction condition, and the impact pressure P acting on each position on the surface of the construction subject 40 by WJP according to the construction condition. A prediction unit 28 that obtains a shock pressure predicted value Pp (distribution of the shock pressure predicted value Pp), which is a predicted value, and a WJP according to a construction condition, after the impact condition predicted value Pp acquired by the prediction unit 28 is used as an input condition. And a residual stress evaluation unit 29 for calculating a residual stress in the construction target 40 of the above.

  Each of the functional units executed by the CPU 20 functions when the CPU 20 executes the WJP evaluation program 34 loaded from the auxiliary storage device 30 into the memory 13 (main storage device). More specifically, in the embodiment shown in FIG. 1, the execution of the flow analysis module 35 of the WJP evaluation program 34 causes the parameter receiving unit 21, the condition receiving unit 22, and the flow analyzing unit 23 to function. In addition, by executing the residual stress analysis module 36 of the WJP evaluation program 34, the target range receiving unit 24, the void ratio / collapse ratio calculating unit 25, the impact pressure correlation value calculating unit 26, the experimental value acquiring unit 27, the predicting unit 28, The stress evaluation unit 29 functions.

  The WJP evaluation by the WJP evaluation device 10 having such a configuration is executed according to the flowchart shown in FIG. That is, FIG. 2 is a diagram illustrating an execution procedure of a WJP evaluation method according to some embodiments. In the following, for simplicity of description, as illustrated in FIG. 3, the surface of the construction target 40 is a plane, and is located on a normal line of the surface (coincides with the injection axis Ai in the example of FIG. 3). A description will be given assuming that a fluid containing water is jetted from a nozzle 50 to an arbitrary point on the surface along a normal line.

  In step S21 of FIG. 2, the evaluator operates the input device 11 of the WJP evaluation device 10 to set various parameters of the flow analysis module 35. In other words, the parameter receiving unit 21 of the WJP evaluation device 10 receives various parameters of the flow analysis module 35 (S21: a parameter setting step of a program (a parameter receiving step)). Upon receiving these parameters, the parameter receiving unit 21 of the WJP evaluation device 10 sets each parameter in a corresponding location of the flow analysis module 35 developed on the memory 13.

  In the embodiment shown in FIG. 2, the flow analysis module 35 includes an LES (Large Eddy Simulation) model for numerically analyzing turbulence and a numerical analysis for behavior of water and a large number of bubbles existing in the water. A two-phase flow model and a cavitation model for numerically analyzing the behavior of bubbles including generation and disappearance of bubbles are adopted. In the parameter setting step (S21), for example, an evaporation coefficient, a condensation coefficient, and a volume ratio of a bubble nucleation site are set as various parameters of the flow analysis module 35. In this parameter setting step (S21), data indicating the atmospheric pressure (water depth D of the construction site), the density and viscosity of water, and the dependence of the saturated vapor pressure on the environment (water temperature, pressure, etc.) are set. By setting WJP execution conditions (described later), the same values as those values at the time of actual execution of WJP are set. Further, in the parameter setting step (S21), the density of the steam is set, and the density of the steam may be set assuming that the steam is, for example, an ideal gas.

  Next, in step S22, WJP execution conditions for the execution target 40 are set (condition setting step (condition receiving step)). For example, when the input device 11 of the WJP evaluation device 10 is operated by the evaluator, the WJP execution conditions are set in the WJP evaluation device 10. In other words, the condition receiving unit 22 of the WJP evaluation device 10 receives WJP construction conditions. This condition setting step (S22) includes a model setting step (model numerical data receiving step) (S22-1) and a WJP execution condition setting step (WJP execution condition receiving step) (S22-2).

  In the model setting process in step S22-1, the condition receiving unit 22 determines whether the construction target model 45 (see FIG. 3), which is a model of the construction target 40, exists in a coordinate system of a space, and numerical data for determining the construction target model 45. In the evening, numerical data for determining a nozzle model 55 (see FIG. 3), which is a model of the nozzle 50 that injects a fluid (water or the like) to the construction target 40, is received. These pieces of information may be stored in the auxiliary storage device 30 as a part of the construction condition data 31.

  In the example of FIG. 3, the coordinate system set in the model setting step (S22-1) has the origin at a point where the injection axis Ai of the nozzle model 55 intersects with the surface of the construction target model 45, and from the origin. This is an XYZ coordinate system in which the direction in which the injection axis Ai extends is the Z axis, the axis perpendicular to the Z axis is the X axis, and the Z axis and the axis perpendicular to the X axis are the Y axis. In FIG. 3, the fluid is ejected from the nozzle model 55 located on the Z axis (ejection axis Ai) in the direction of the origin along the Z axis (ejection axis Ai). In the XYZ coordinate system, the position of the outlet 51o on the injection axis Ai at the initial position of the nozzle model 55 may be set as the origin.

  In the above-described numerical data for determining the construction target model 45, in the example of FIG. 3, since the surface of the construction target 40 is a plane, information indicating that the surface of the construction target model 45 is a plane is set. Will be.

  The above-described numerical data that determines the nozzle model 55 is numerical data that can represent the nozzle 50 that ejects a fluid used in actual WJP construction. For example, in the actual nozzle 50, as shown in FIG. 4, a flow path is formed along an injection axis Ai penetrating from one end face of the cylindrical member to the other end face, and one end face of the nozzle 50 is formed. The opening of the flow path at, forms the inlet 51i, and the opening of the flow path at the other end surface forms the outlet 51o. The flow path has a reduced diameter portion 52 whose diameter gradually decreases toward the outlet 51o, a small diameter portion 53 in which the reduced flow diameter is maintained by the reduced diameter portion 52, and a small diameter portion 53. And a diameter-enlarging portion 54 in which the flow path diameter gradually increases from the outlet to the outlet.

  For such a nozzle 50 (FIG. 4), numerical data for determining the nozzle model 55 include, for example, a flow path diameter di of the inlet 51 i of the nozzle 50, a flow path diameter ds of the small diameter portion 53, and a flow path diameter do of the outlet 51 o. The length Ni of the reduced diameter portion 52 in the direction of the injection axis Ai, the length Ns of the small diameter portion 53 in the same direction, and the length No of the enlarged diameter portion 54 in the same direction may be used. In the present embodiment, the shape of the nozzle 50 described above is used as the shape of the nozzle 50. However, in some other embodiments, a nozzle model of another shape may be used. Are set in the model setting step (S22-1).

  On the other hand, in the WJP execution condition setting step in step S22-2, the condition receiving unit 22 receives each condition as a WJP execution condition so as to affect the WJP execution result. The WJP execution conditions include, for example, the discharge pressure of the jet from the nozzle 50, the flow rate of the jet from the nozzle 50, and the jet distance G (the distance from the outlet 51o of the nozzle 50 to the surface of the construction target 40) ( (See FIG. 3), the angle θ between the injection axis Ai of the nozzle 50 and the normal of the surface of the construction target 40 (the inclination angle of the construction target surface), the water depth D of the construction target surface, the water temperature, The injection time t of the fluid, the injection speed from the nozzle 50, the flow velocity, the execution range S, the bubble radius, the nozzle angle φ which is the angle formed between the surface to be installed and the injection axis Ai of the nozzle 50, and the pitch which is the execution interval of WJP In the WJP execution condition setting step (S22-2), at least one of these conditions is accepted. These may be stored in the auxiliary storage device 30 as a part of the construction condition data 31. In the embodiment shown in FIG. 2, the program parameters set in step S21 and the WJP execution conditions set in step S22 are separately set, but the parameters set in step S21 are also set in WJP. May be set as various types of construction conditions. Then, the analysis of the jet under the conditions set in the condition setting step (S22) is executed in the next step S23 (S23: analysis step).

The analysis step (S23) in step S23 includes a flow analysis step (S23-1) and a calculation step (S23-2) of the void rate f and the collapse rate η.
In this flow analysis step (S23-1), the flow analysis unit 23 analyzes the jet under the conditions set in the WJP condition setting step (S22), and at each position on the surface of the construction target model 45 The number of generated bubbles and the number of disappeared bubbles at each time are calculated. This analysis result may be stored in the auxiliary storage device 30 as the flow analysis data 32. More specifically, in this flow analysis step (S23-1), in some embodiments, the number of generated bubbles and the number of disappeared bubbles at each time on each position on the surface of the construction target model 45 are as follows. To ask.

  That is, using the model (for example, the above-described two-phase flow model and cavitation model) set in the parameter setting step (S21), the CFD (for example, the unsteady state) is performed under the conditions set in the condition setting step (S22). Analysis by LES (Large Eddy Simulation) is performed. The analysis is usually performed until sufficient statistical information is obtained. This analysis may be performed using a calculation function such as the analysis code FLUENT of ANSYS. For the caption model, see, for example, Philip J. et al. Zwart, Andrew G .; Gerber, Thabet Belamri: "A Two-Phase Flow Model for Predicting Cavitation. Dynamics", ICMF 2004 International Conference, No. 3, January, March, January, 2010. 152 may be used.

In the subsequent step S23-2, after the flow analysis step (S23-1) is completed, the void rate / collapse rate calculation unit 25 calculates the void rate f and collapse rate η for bubbles at each position on the surface of the construction target model 45. Is calculated (S27: Step of calculating void ratio f and collapse ratio η).
Here, the void fraction f is the volume fraction of bubbles contained in a unit volume of a fluid containing water, and the decay rate η is the volume fraction of bubbles that collapse in a unit time in a unit volume of a fluid containing water. It is. The void rate / collapse rate calculation unit 25 uses the flow analysis data 32 stored in the auxiliary storage device 30 or the memory 13 to calculate the injection time in the unit volume of the fluid at each position on the surface of the construction target model 45. The volume ratio of air bubbles per unit time is determined. Further, the void rate / collapse rate calculation unit 25 uses the flow analysis data 32 stored in the auxiliary storage device 30 or the memory 13 to calculate, in the unit volume of the fluid at each position on the surface of the construction target model 45, From the number of disappearing bubbles at each time, the volume ratio of bubbles that collapse in a unit time including the time in the unit volume of the fluid at each position on the surface of the construction target model 45 is determined. In the embodiment illustrated in FIG. 2, the void ratio / collapse ratio calculation unit 25 sets the average value of the volume ratio per unit time as the void ratio f, and calculates the average value of the volume ratio of the bubbles that collapse in each unit time. It is calculated as the decay rate η. In some other embodiments, the values are not limited to the average value, and values obtained by other statistical methods may be used as the void rate f and the decay rate η.

In step S24, after completion of the analysis step (S23), the impact pressure correlation value calculation unit 26 calculates an impact pressure correlation value at each position on the surface of the construction target model 45 based on the void rate f and the collapse rate η. (S24: Impact pressure correlation value calculation step). More specifically, the actual impact pressure P by WJP is, as an empirical rule, a coefficient k depending on a bubble collapse rate η, a bubble void rate f, a water depth D, and a jet flow rate as shown in the following equation. It can be expressed by the product of
P = k × η × f

  Therefore, the product of the void ratio f of the bubble and the collapse ratio η of the bubble in the above equation is calculated as the impact pressure correlation value Pc. That is, the shock pressure correlation value calculation unit 26 multiplies the void rate f at each position on the surface of the construction target model 45 by the collapse rate η at the position to obtain the shock pressure correlation value Pc at each position. (Distribution of impact pressure correlation value Pc) is obtained.

In step S25, an impact pressure experimental value Pr, which is an experimental value of the impact pressure P acting on the surface of the construction target 40, is obtained by WJP under the same construction conditions used in the analysis step (S23) (S25: experiment). Value acquisition step). The shock pressure experimental value Pr may be acquired by loading measurement data (impact pressure experimental value Pr) of the shock pressure P obtained by performing WJP on the test piece in advance into the WJP evaluation program 34. The loading of the shock pressure experimental value Pr by the WJP evaluation program 34 may be performed by inputting by the evaluator or by reading from the auxiliary storage device 30.
Then, a prediction step (S26) is performed based on the data obtained in the shock pressure correlation value calculation step (S24) and the experimental value acquisition step (S25).

  In the prediction step in step S26, the impact pressure correlation value Pc at each position on the surface of the construction target model 45 and the effect on the surface of the construction target 40 by WJP under the same construction conditions used to calculate the shock pressure correlation value Pc. The impact pressure experimental value Pr is associated with the impact pressure predicted value Pp (the distribution of the impact pressure predicted value Pp), which is the predicted value of the impact pressure P acting on each position on the surface of the construction target 40 by WJP under the construction conditions. ) Is obtained.

More specifically, since the impact pressure P is proportional to the impact pressure correlation value Pc according to the above-described mathematical expression representing the empirical side, the correlation between the impact pressure P and the impact pressure correlation value Pc obtained through an experiment is the highest. The above coefficient k is obtained. That is, the impact pressure prediction value Pp is determined by determining a coefficient k that associates the impact pressure correlation value Pc (distribution of the impact pressure correlation value Pc) at each position on the surface of the construction target model 45 with the impact pressure experimental value Pr. Is obtained. More specifically, the difference between the position of the construction target surface at which the shock pressure experimental value Pr was obtained and the shock pressure correlation value Pc corresponding to this position is calculated for each of the positions at which the shock pressure experimental value Pr was obtained. This is done by finding a coefficient k that makes these differences fall within a certain range.
For example, the coefficient k may be obtained by the least square method.

  The relationship among the shock pressure correlation value Pc, the shock pressure experimental value Pr, and the shock pressure predicted value Pp will be described with reference to FIG. That is, FIG. 5 is a diagram for explaining the relationship among the shock pressure correlation value Pc, the shock pressure experimental value Pr, and the shock pressure predicted value Pp, corresponding to FIG. In FIG. 5, the center of the injection axis Ai of the nozzle 50 (nozzle center O) is the intersection of the horizontal axis and the vertical axis, and the position from the nozzle center O is indicated by the horizontal axis. Pr (circle) is indicated by the vertical axis. FIG. 5 shows two different impact pressure experimental values Pr in which the injection time t (sec) is 2 seconds (filled circle) and 10 seconds (open circle). When compared at the same position on the target surface, the experimental value Pr of the impact pressure shows a larger value when the injection time is 10 seconds than when the injection time is 2 seconds.

  On the other hand, in FIG. 5, the above-described shock pressure correlation value Pc is indicated by a broken line, but in the example of FIG. 5, the shock pressure correlation value Pc is a large value at each position when compared with the shock pressure experimental value Pr. It has become. The impact pressure correlation value Pc is, as described above, the void ratio f × the collapse pressure η. In other words, the impact pressure correlation value Pc can be said to be a value when the coefficient k in the above equation is set to 1. That is, the reason why the shock pressure correlation value Pc and the shock pressure experimental value Pr are greatly different at each position is that the coefficient k that associates the shock pressure experimental value Pr with the shock pressure correlation value Pc is not set.

  The shock pressure predicted value Pp obtained by associating the two with each other in the above-described prediction step (S26) is the shock pressure predicted value Pp shown in the example of FIG. Corresponding to the shock pressure experimental value Pr, the shock pressure predicted value Pp indicated by the bold line corresponds to the shock pressure experimental value Pr for the injection time of 10 seconds. Both of these two predicted impact pressure values Pp are symmetric with respect to the center O of the nozzle. This is because, in FIG. 3, since the normal line of the construction target model 45 which is a flat surface coincides with the injection axis Ai of the nozzle model 55, the isopressure line Pe of the impact pressure P is concentrically formed from the nozzle center O. This is because they are distributed (see FIG. 6A). In the case where the normal line of the construction target model 45 does not coincide with the nozzle model 55, the distribution of the impact pressure P on the construction target surface is different from that in FIG. 6A. For example, in FIG. The iso-pressure lines Pe are distributed.

  In step S27, the residual stress in the construction target 40 after WJP is constructed according to the construction conditions is calculated using the impact pressure predicted value Pp acquired in the prediction step (S26) as an input condition. That is, residual stress is calculated by performing, for example, FEM analysis based on the impact pressure predicted value (S27: residual stress analysis step).

  According to the above embodiment, by analyzing the occurrence and disappearance of cavitation bubbles in water jet peening (WJP), the actual impact pressure due to WJP generated near the construction target surface is predicted, and the predicted impact pressure is calculated. Based on the result, the residual stress after WJP construction can be evaluated.

  In some embodiments described above, the residual stress near the surface of the construction target 40, which is improved by WJP under the set construction conditions, is evaluated. In some other embodiments, WJP application conditions are determined based on the evaluation results of the residual stress evaluated in this manner. This means that, when the specifications of the plant (for example, the size of the nozzle 62 to be welded to the end plate 61) are different, the reliable WJP construction conditions that can correspond to the specifications of each plant are quickly determined. It is assumed that.

  For example, in the examples of FIGS. 7A and 7B, the specifications of the cylindrical nozzle 62 used in the plant are different. Specifically, the diameter L1 of the nozzle 62 illustrated in FIG. 7A is smaller than the diameter L2 of the nozzle 62 illustrated in FIG. 7B. The interval W1 between the plurality of nozzles 62 in FIG. 7A is wider than the interval W2 between the nozzles 62 in FIG. 7B, and the angle φ between the nozzle 50 and the construction surface is different accordingly. Specifically, the angle φ1 in FIG. 7A is smaller than the angle φ2 in FIG. 7B (angle φ1 <angle φ2). Further, since the magnitude of the impact pressure P by WJP depends on the distance from the nozzle center O (see FIGS. 5 to 6B), the effect of improving the residual stress by WJP depends on the size of the working range S. For this reason, the working range S is appropriately set in order to obtain a desired improvement effect. In FIG. 7A, WJP is performed around the nozzle 62 at a 90-degree pitch. That is, the nozzle 50 is positioned around the nozzle 62 every 90 degrees, and WJP is performed at each of the determined positions, and the entire circumference of the nozzle 62 is performed by a total of four WJPs. On the other hand, in FIG. 7B, the circumference of the nozzle 62 is wider, and the WJP is performed on the circumference of the nozzle 62 at a pitch of 45 degrees. If the application conditions are different as described above, the effective range of the residual stress reduction applied for one pitch of the nozzle 50 is different. Needs to be confirmed.

For this reason, in some embodiments, as shown in FIG. 8, the WJP evaluation device 10 further includes a target value setting unit 210 that sets a target value of residual stress, in addition to the functional units illustrated in FIG. 1. A construction condition changing unit 211 for changing construction conditions when the residual stress does not satisfy the target value, and constructing the construction conditions used for calculating the residual stress on the construction object 40 when the residual stress satisfies the target value. And a construction condition determining unit 212 that determines the condition. When these functions are executed by the computer (CPU 20), the CPU 20 executes the WJP evaluation program 34 loaded from the auxiliary storage device 30 into the memory 13 (main storage device). It works by doing. More specifically, in the embodiment shown in FIG. 8, the execution of the flow analysis module 35 of the WJP evaluation program 34 causes the target value setting unit 210, the construction condition changing unit 211, and the construction condition determining unit 212 to function. I have.
Hereinafter, the execution procedure of the WJP evaluation method according to the present embodiment will be described with reference to the flowchart shown in FIG.

  In step S90 of FIG. 9, a target value of the residual stress is set (S90: target value setting step). The target value may be, for example, that the residual stress is 0 or less in the construction range S. In addition, for example, the target value input by the evaluator is received and set to be used in the WJP evaluation program 34. Thereafter, the same evaluation as the above-described evaluation of the residual stress (see steps S21 to S27 in FIG. 2) is performed. That is, steps S91 to S97 in FIG. 9 are the same as steps S21 to S27 in FIG. 2, respectively, and thus description of each step is omitted.

  In the following step S98, the calculated residual stress is compared with the previously determined target value (step S90). If the residual stress does not satisfy the target value, the WJP execution conditions are changed in step S99 (S99: execution condition changing step). Specifically, at least one of the various conditions set in the WJP construction condition setting step (S92) is changed. For example, the jet time of the water jet by the water jet peening, the jet speed of the water jet, the flow rate of the water jet, the working range S of the water jet peening, the jet distance of the water jet, the radius of the bubble, the nozzle angle φ , At least one of the inclination angles θ of the construction target surface. Then, the residual stress is evaluated again based on the new WJP execution conditions changed in the execution condition changing step (S99) (S91 to S97).

  If the calculated residual stress satisfies the target value in step S98, the execution condition used to calculate the residual stress is determined as the actual execution condition for the execution target 40 in step S910. You. Then, the flow ends.

  When the coefficient k corresponding to the construction condition has been obtained in advance, the experimental value acquisition step (S95) and the prediction step (S96) are omitted, and instead, the impact pressure correlation value calculation step (S94) The shock pressure prediction value Pp obtained based on the shock pressure correlation value Pc and the coefficient k obtained in the step S) may be directly adopted as an input condition for the residual stress analysis (S97). In addition, based on the evaluation results of the residual stress, the specifications of the WJP construction equipment such as the function and shape of the nozzle 50 are examined, and the design is used to design a WJP construction equipment capable of performing construction under the construction conditions satisfying the above target values. May be.

  According to the above embodiment, even when WJP is constructed under construction conditions that have no track record in accordance with the specifications of the plant, the residual stress after WJP construction can be evaluated by analysis. Appropriate construction conditions can be determined promptly. Furthermore, reliable WJP construction can be performed by actually constructing WJP according to the construction conditions determined in this way. Further, the present invention can be used for designing a WJP construction apparatus capable of performing construction under desired construction conditions.

  In some other embodiments, the residual stress, flow analysis data 32, collapse rate η, void fraction f, impact pressure correlation value Pc, impact pressure experimental value Pr, coefficient k, Related information such as the impact pressure predicted value Pp may be stored in a database and used. This makes it possible to easily obtain related information from the construction conditions stored in the database.

The present invention is not limited to the above-described embodiment, and includes a form in which the above-described embodiment is modified and a form in which these forms are appropriately combined.

Reference Signs List 10 evaluation device 11 input device 12 display device 13 memory 14 input / output interface 15 communication interface 16 storage / playback device

20 CPU
21 Parameter Receiving Unit 22 Condition Receiving Unit 23 Flow Analysis Unit 24 Target Range Receiving Unit 25 Void Fraction / Collapse Rate Calculation Unit 26 Impact Pressure Correlation Value Calculation Unit 27 Experimental Value Acquisition Unit 28 Prediction Unit 29 Residual Stress Evaluation Unit

Reference Signs List 30 auxiliary storage device 31 construction condition data 32 flow analysis data 33 processing range data 34 evaluation program 35 flow analysis module 36 residual stress analysis module 37 OS program

40 Construction target 45 Construction target model

50 Nozzle 51i Inlet 51o Outlet 52 Reduced diameter part 53 Small diameter part 54 Large diameter part 55 Nozzle model

61 head plate 62 nozzle

Ai Injection axis D Water depth G Injection distance M Disk-type storage medium P Impact pressure Pc Impact pressure correlation value Pe Isopressure line Pp Impact pressure predicted value Pr Impact pressure experimental value

di Inlet flow path diameter do Outlet flow path diameter ds Flow path diameter f Void fraction k Coefficient t Injection time O Nozzle center L1 Diameter of nozzle L2 Diameter of nozzle W1 Diameter of nozzle Nozzle W2 Distance of nozzle Nozzle S Construction range φ Nozzle angle

Claims (12)

A condition setting step of setting water jet peening construction conditions for the construction object,
Analyzing the jet flow when the fluid is jetted from the nozzle model to the construction target model according to the construction conditions, at each position on the surface of the construction target model where the distribution of the impact pressure by the jet flow occurs , the flow of the fluid Analysis step to determine the void fraction, which is the volume fraction of bubbles contained in the unit volume, and the collapse rate, which is the volume fraction of the bubbles that collapse in a unit time in the unit volume of the fluid,
Impact pressure correlation value calculation step of obtaining an impact pressure correlation value that is a product of the void rate and the collapse rate at each position,
It is an experimental value of the actual impact pressure at at least one position on the actual surface that is the surface of the application target or the test piece when the actual impact pressure distribution is generated by the water jet peening under the application condition. An experimental value acquiring step of acquiring an impact pressure experimental value,
The acquired impact pressure experimental value and the positional relationship in the distribution of the impact pressure on the surface of the construction target model are the actual impact pressure at the position on the actual surface where the impact pressure experimental value was acquired. by determining said impact pressure correlation value at position of the surface of the working object model, such as the same as the positional relationship in the distribution, Ru the association coefficients, the working object by said water jet peening by the working conditions A prediction step of obtaining a shock pressure prediction value that is a prediction value of the shock pressure acting on each position of the surface of the,
A residual stress evaluation step of calculating a residual stress in the construction target after performing the water jet peening according to the construction condition, using the impact pressure predicted value acquired in the prediction step as an input condition, Residual stress evaluation method. A target value setting step of setting a target value of the residual stress,
An execution condition changing step of changing the execution condition when the residual stress does not satisfy the target value,
The analysis step, the impact pressure correlation value calculation step, and the re-evaluation step of performing the residual stress evaluation step by the changed execution condition changed by the execution condition changing step,
When the residual stress calculated by the re-evaluation step satisfies the target value, a construction condition determination step of determining the construction condition used in the re-evaluation step as the construction condition for the construction target, The residual stress evaluation method according to claim 1, further comprising: If the residual stress calculated by the reevaluation step does not satisfy the target value, further change the execution condition by the execution condition change step, the changed execution condition further changed by the execution condition change step The residual stress evaluation method according to claim 2 , wherein the re-evaluation step is performed by: The execution conditions are: water jet injection time by the water jet peening, the water jet injection speed, the water jet flow rate, the water jet peening execution range, the water jet injection distance, the bubble radius, and the nozzle. The residual stress evaluation method according to any one of claims 1 to 3 , further comprising at least one of an angle and an inclination angle of the surface to be applied. On the computer,
A condition setting step of setting water jet peening construction conditions for the construction object,
Analyzing the jet flow when the fluid is jetted from the nozzle model to the construction target model according to the construction conditions, at each position on the surface of the construction target model where the distribution of the impact pressure by the jet flow occurs , the flow of the fluid Analysis step to determine the void fraction, which is the volume fraction of bubbles contained in the unit volume, and the collapse rate, which is the volume fraction of the bubbles that collapse in a unit time in the unit volume of the fluid,
Impact pressure correlation value calculation step of obtaining an impact pressure correlation value that is a product of the void rate and the collapse rate at each position,
It is an experimental value of the actual impact pressure at at least one position on the actual surface that is the surface of the application target or the test piece when the actual impact pressure distribution is generated by the water jet peening under the application condition. An experimental value acquiring step of acquiring an impact pressure experimental value,
The acquired impact pressure experimental value and the positional relationship in the distribution of the impact pressure on the surface of the construction target model are the actual impact pressure at the position on the actual surface where the impact pressure experimental value was acquired. by determining said impact pressure correlation value at position of the surface of the working object model, such as the same as the positional relationship in the distribution, Ru the association coefficients, the working object by said water jet peening by the working conditions A prediction step of obtaining a shock pressure prediction value that is a prediction value of the shock pressure acting on each position of the surface of the,
A residual stress evaluation step of calculating a residual stress in the object after the water jet peening according to the application condition, using the impact pressure predicted value obtained in the prediction step as an input condition; and Jet peening evaluation program. A target value setting step of setting a target value of the residual stress,
An execution condition changing step of changing the execution condition when the residual stress does not satisfy the target value,
The analysis step, the impact pressure correlation value calculation step, and the re-evaluation step of performing the residual stress evaluation step by the changed execution condition changed by the execution condition changing step,
When the residual stress calculated by the re-evaluation step satisfies the target value, a construction condition determination step of determining the construction condition used in the re-evaluation step as the construction condition for the construction target, The water jet peening evaluation program according to claim 5 , which is further executed. If the residual stress calculated by the reevaluation step does not satisfy the target value, further change the execution condition by the execution condition change step, the changed execution condition further changed by the execution condition change step 7. The water jet peening evaluation program according to claim 6 , wherein the re-evaluation step is performed by: The execution conditions are: water jet injection time by the water jet peening, the water jet injection speed, the water jet flow rate, the water jet peening execution range, the water jet injection distance, the bubble radius, and the nozzle. The water jet peening evaluation program according to any one of claims 5 to 7 , wherein the program includes at least one of an angle and an inclination angle of a surface of the construction target. A condition receiving unit for receiving water jet peening construction conditions for the construction object,
Analyzing the jet flow when the fluid is jetted from the nozzle model to the construction target model according to the construction conditions, at each position on the surface of the construction target model where the distribution of the impact pressure by the jet flow occurs , the flow of the fluid An analysis unit that determines a void fraction that is a volume fraction of bubbles contained in a unit volume, and a collapse rate that is a volume fraction of the bubbles that collapses in a unit time in a unit volume of the fluid,
An impact pressure correlation value calculation unit that determines an impact pressure correlation value that is a product of the void rate and the collapse rate at each of the positions,
It is an experimental value of the actual impact pressure at at least one position on the actual surface that is the surface of the application target or the test piece when the actual impact pressure distribution is generated by the water jet peening under the application condition. An experimental value acquiring unit for acquiring an impact pressure experimental value;
The acquired impact pressure experimental value and the positional relationship in the distribution of the impact pressure on the surface of the construction target model are the actual impact pressure at the position on the actual surface where the impact pressure experimental value was acquired. by determining said impact pressure correlation value at position of the surface of the working object model, such as the same as the positional relationship in the distribution, Ru the association coefficients, the working object by said water jet peening by the working conditions A prediction unit that obtains an impact pressure predicted value that is a predicted value of the impact pressure acting on each position on the surface of the
With the impact pressure prediction value obtained by the prediction unit as an input condition, a residual stress evaluation unit that calculates a residual stress in the construction target after performing the water jet peening under the construction condition, Water jet peening evaluation device. A target value setting unit for setting a target value of the residual stress,
An execution condition changing unit that changes the execution condition when the residual stress does not satisfy the target value,
When the residual stress satisfies the target value, further comprising a construction condition determining unit that determines the construction conditions used for calculating the residual stress as the construction conditions for the construction target,
The re-evaluation is performed by the analysis unit, the impact pressure correlation value calculation unit, and the residual stress evaluation unit according to the changed execution condition changed by the execution condition changing unit,
When the residual stress calculated by the reevaluation satisfies the target value, the execution condition determining unit determines the execution condition used in the reevaluation as the execution condition for the execution target. The water jet peening evaluation device according to claim 9 , wherein: When the residual stress calculated by the re-evaluation does not satisfy the target value, further change the execution condition by the execution condition changing unit, and by the changed execution condition further changed by the execution condition changing unit. The water jet peening evaluation apparatus according to claim 10 , wherein the reevaluation is performed. The execution conditions are: water jet injection time by the water jet peening, the water jet injection speed, the water jet flow rate, the water jet peening execution range, the water jet injection distance, the bubble radius, and the nozzle. The water jet peening evaluation apparatus according to any one of claims 9 to 11 , wherein the evaluation apparatus includes at least one of an angle and an inclination angle of the surface to be applied.

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